Discovery, acquisition, refinement, use, recovery, and remediation of naturally occurring hydrocarbons such as petroleum products, minerals, and other materials can be complex, expensive, and environmentally challenging. Various devices and methods have been developed over the years to solve or aid these challenges and concerns.
In the area of petroleum exploration and production from terrestrial sources, pressurized fracturing fluids are sometimes used. The pressurized fracturing fluids are injected into putative or operational oil wells, creating cracks in geological formations at or near sources of petroleum products. The cracks allow oil and gas to escape from beneath the surface of the earth. The oil and gas are collected with particularized apparatuses at the surface. The fracturing fluids are also released in the process. The hydraulic fracturing fluids are emitted from the earth as a mixture of water, various chemicals, hydrocarbons, natural occurring substances, and proppants. A goal in industry is to sufficiently cleanse water from used fracturing fluids for reuse in making fresh fracturing fluid for further fracturing operations. Another goal is to cleanse water found in used fracturing fluids to a degree where it is environmentally acceptable for disposal at an above-ground location or facility. An ultimate goal is to cleanse water from used fracturing fluid to a point where it is in the form of potable water.
In addition to fracturing fluids, water is often found in crude oil obtained from an oil well. Separation of water from the crude oil is performed above ground. The separation technique used is typically a static gravity collection system consisting of large holding tanks in combination with an oil—water separator system. This process usually requires a long time for the oil and water mixture to separate as it resides in the large holding tanks. As a result, oil—water separator systems are not particularly efficient or cost effective.
Water is also used to obtain crude oil, gas, and other petroleum products from submarine locations. The water used in submarine, or off shore, oil production usually becomes contaminated with a variety of substances during the production process. Off shore oil wells produce a substantial amount of “sour water” in the course of pumping crude oil. The sour water is usually a mixture of brackish water, hydrogen sulfide, hydrogen sulfide ions, and various hydrocarbons. A significant problem associated with using sour water is the sulfur content of the sour water. Sulfur in sour water is primarily found it two forms—hydrogen sulfide and hydrogen sulfide ions. In addition to sulfur compounds in sour water, hydrocarbons and other petroleum products or compounds are problematic in sour water. If sulfur containing compositions, petroleum products, and volatile compounds could be substantially removed from sour water, the sour water would be rendered sufficiently clean to be responsibly returned to the ocean or disposed of on land. In addition, water is often found in crude oil, gas, and other petroleum products obtained in an off shore production process. Separating water from these materials would enable the materials to be utilized rather than remaining of little or no use and in some cases hazardous.
One method of cleansing sour water or removing water from fracturing fluids, petroleum, and petroleum products involves reacting or mixing a gaseous composition, such as air, carbon dioxide, or other appropriate gas with these materials under certain conditions. In some circumstances, for example, an air sparged hydrocyclone apparatus is used for the flotation or cleaning of coal, for the flotation or processing of tar sands, and for separating minerals from their host material by flotation. U.S. Pat. Nos. 4,279,743; 4,397,741; and 4,399,027, each issued to Miller, disclose an air sparged hydrocyclone apparatus. While the apparatuses of Miller and others may be able to separate solid materials from water, the solids are often recovered in relatively small amounts. In practice, recovery of small amounts of solid materials with these apparatuses and methods is usually below the requirements of industry. Furthermore, Miller does not disclose an apparatus or method capable of separating hydrocarbons, volatile organic compounds, or sulfur-containing compounds from water.
Shumeng, et al. disclose an air sparged hydrocyclone unit in published Chinese patent application No. 200620148747.2 (Patent ID: CN 200981025 Y). According to Shumeng, et al., the hydrocyclone unit is used for separating oil from water. In contrast with the present invention, the apparatus of Shumeng, et al. does not utilize negative pressure in conjunction with the apparatus. Nor does the hydrocyclone unit of Shumeng et al. have unrestricted outflow through a lower opening in the apparatus. Rather, a tapered outlet restricts outflow from the unit.
Kalnins discloses a hydrocyclone unit in Published PCT application No. WO 88/09696. The hydrocyclone unit utilizes a pressure-reducing device in the form of a venturi positioned at the end of a fluid inlet where inflowing contaminated liquid is introduced to the lower end of the hydrocyclone unit. The negative pressure created by the venturi increases the rate of flow of the inflowing contaminated liquid. Kalnins does not use negative pressure to separate hydrocarbons, volatile organic compounds, or sulfur-containing compositions from liquids, such as water. Nor does the hydrocyclone unit of Kalnins provide unrestricted outflow of water and contaminants from the unit.
None of these references discloses an apparatus or method capable of eliminating or substantial reducing contaminants such as hydrocarbons, volatile organic compounds, sulfur, hydrogen sulfide, hydrogen sulfide ions, crude oil, or other petroleum products from water.